Jim Day
Ansys Employee
If you're talking about a local coordinate system for the purpose of orienting material directions in an orthotropic/anisotropic material model, no such system should be needed. The variable AOPT in the *MAT input may be set to 0, in which case the element coordinate system as determined by the nodal connectivity will serve to orient the material coordinate system. See Remarks in the description of *MAT_002 in the LS-DYNA User's Manual for details.